Spatial and temporal dispersal patterns of Diachasmimorpha longicaudata (Hymenoptera: Braconidae) reared on Ceratitis capitata and Anastrepha fraterculus (Diptera: Tephritidae)

Abstract

The dispersal and parasitism abilities of Diachasmimorpha longicaudata, reared on the larval hosts Ceratitis capitata and Anastrepha fraterculus, were evaluated in a guava orchard. Eleven releases of approximately 3000 parasitoids were conducted in a 15-ha orchard and wasp dispersal was monitored from 6 to 272 m away from a central release point. At each monitoring point, larvae of C. capitata and A. fraterculus were offered as hosts for the parasitoids. In five releases, parasitoids were offered only one host species, and in six releases, they were given a choice. In total, 10,351 parasitoids were recovered from these hosts, all of which were D. longicaudata. Both parasitoid strains dispersed in all directions, but showed a slight bias towards the east. Both strains of the parasitoid survived and parasitized larvae of A. fraterculus and C. capitata for up to 15 days after release, with maximum activity during the first 7 days, but more individuals of the Anastrepha strain were recovered after 15 days. Although the highest rates of parasitism by both wasp strains occurred close to the release point, the Anastrepha strain parasitized more hosts at greater distances from the release point, whereas the Ceratitis strain parasitized more hosts close to release points. Releases of the Anastrepha strain of D. longicaudata are therefore recommended, as this strain yields high rates of parasitism further away from release points and appears to survive longer in the field.